Recently, wearable computing products are introduced to more conveniently use portable computers, but these need shapes and elements for better stability and functionality.
Since existing smart-glasses, which are one of wearable computing products, are provided with only one transparent screen, it is inconvenient to use the same in a bright region, and these smart-glasses provide a fixed function which recognizes only the front view.
Also, as one of wearable computing products, a head-mounted display is an apparatus which generates an image using a display device such as a liquid crystal display device (LCD), magnifies the generated image into an enlarged scale to be viewed, and is used to view the image as mounted on the head of a human, and since the head-mounted display is designed mainly for use in a closed area only, the head-mounted display has a limitation that it may be inconvenient for mobile use and not be safely used in motion.
That is, the head-mounted display provides an excellent image, but is not suitable for normal wearing due to limitations of the structure, and a user is unable to move wearing the head-mounted display due to lack of transparency.